一下哪一项与阿司匹林的性质不符（） ["A具退热作用","B遇湿会水解成水杨酸和醋酸","C极易溶解于水","D具有抗炎作用","E有抗血栓形成作用"]
简述有效保护及其政策意义。
盐酸吗啡溶液遇甲醛硫酸试液呈（） ["A绿色","B蓝紫色","C棕色","D红色","E不显色"]
盐酸吗啡水溶液的PH值为（） ["A1-2","B2-3","C4-6","D6-8","E7-9"]
吩噻嗪第二位上为哪个取代基时，其安定作用最强（） ["A，–H","B，-CL","C，COH3","D，CF3.","E，–CH3"]
简述非关税壁垒的主要特点
